What are the features of the structure of mosses? The structure of moss "kukushkin flax"

What are the features of the structure of mosses? In their structure, they resemble algae, but, unlike them, most moss species have a stem and leaves. Rhizoids, which resemble roots, help them stay on the surface and absorb water. For mosses is characterized by a fairly wide range of habitats. Most of them prefer wet, shady places, often around the base of the trees. But there are also those who love light, and grow as epiphytes on tree branches or on open areas, such as clay banks and the edges of paths. All sphagnum or peat mosses grow on lakes and marshes, where the water is standing all year round.

Appearance

Most of the mosses are small, green leafy plants attached to the soil, bark of trees or stones with thin filiform roots, which are called rhizoids. Some species can have single upright stems, while others have branching stems and resemble a soft green carpet covering the soil. In New Zealand, the highest moss (Dawsonia superba) grows, reaching a height of half a meter, but most species reach about 1-2 centimeters in height.

Surviving in harsh conditions

Real masters of suspended animation, such as mosses, can withstand the action of high temperature (up to 70 ° C) for a long time, and with the return of moisture they come back to life again. This amazing form of life will grow in deep, dense forests and caves, where the intensity of light is insufficient for the favorable growth of any other green plant. In the high latitudes of the Arctic, mosses are one of the few plant forms that can survive the devastating cold. Many species can favorably exist in hard-to-reach cracks and crevices where most plants simply could not survive. They do not die even when they dry up. In droughty periods, their metabolism is turned off until the rains return, when their processes are restarted, and all vital functions are restored. The features of the moss structure help in this. These primitive plants are considered among the first to develop the ability to live on land.

Ubiquitous disputes

The released moss spores can travel long distances in the wind and remain viable for decades. After finding a comfortable environment, they settle and begin to produce hairy filaments. From the spores, the threads that grow to the surface with the help of rhizoids sprout. The structure of the moss is represented by a gametophyte, which includes the stem and leaves, where the process of photosynthesis takes place, during which sunlight is converted into nutrient energy. What are the features of the structure of mosses? Mosses do not have full leaves, instead of them on the stems are arranged in a spiral tiny processes in the form of flat scales or flakes.

Mosses: Structure and Reproduction

Although mosses do not bloom, in some species shoots with male genital organs may look like small green flower heads. Reproduction occurs under the open sky, it is not hidden inside the flowers. Anterozoids are released into small pouches, in order to fertilize the egg of neighboring cells. In the stem there is a spore capsule, called sporangium, it can release up to a million spores. Maturation occurs under a special coating, which dries up and falls off when it is no longer necessary. The mature spores are released and leave the capsule to form new plants.
Mosses do not depend only on sexual reproduction. Gametophytes have balls from unspecialized cells attached to them. If one of the wrecked obogov has broken off, then one simple cell is enough to form a new one. This ensures the survival of the plant under adverse conditions. The peculiarities of the structure of mosses, the simplicity of construction and several methods of reproduction allow them to find their habitat everywhere from the polar circle to the equator. These are surprisingly stable and versatile plants.

Biology and Evolution

There is an assumption that mosses are the common ancestor of all terrestrial plants. Modern science distinguishes more than 10,000 species adapted to the most diverse habitats, from reservoirs to the desert. Despite the fact that the structure of moss is constructively simple, gametophytes contain different types of cells. In response to dehydration, cells resume division and differentiate into thick-walled, stented cells that undergo programmed cell death. Life resumes after the plant enters favorable conditions. Mkham managed to preserve the primitive aspects of the cellular structure and composition, as well as the amazing ability to adapt, which allowed them to inhabit a variety of habitats.

Features of the structure

What are the features of the structure of mosses? The structure includes a stem, leaves, axillary hair and rhizoids. The stem, as a rule, consists of small thick-walled epidermal cells, thin-walled parenchyma cells and conducting cells. Conductive cells include hydroids and leptoids. Leaves, as a rule, consist of one layer of cells, with the exception of veins and fields, which can consist of several layers of differentiated cells. On the stem there is sporophyte, sporangium, spores, which also consist of specialized cell types.

Advantages of the moss structure

What are the features of the structure of mosses, we have already found out, now their structural advantages should be considered. Since mosses receive all nutrients from the air, since they do not have real roots, these unpretentious plants require only a shadow, acid soil and sufficient moisture. The preferred habitat is infertile soil with a low content of nutrients in water. In addition to good adaptability, mosses have a good ability to produce large volumes of tissue consisting of a single cell type, as well as rapid regeneration of protoplasts in the cell wall.

Kukushkin flax

The structure of moss of Kukushkin flax is represented by thin brownish stems densely covered with small dark green leaves. This perennial plant often covers damp places with a dense carpet, used for medical purposes. Kukushkin flax grows in the tundra, in swamps, in mountains, forests and meadows. It forms a sod pillow or merges into one continuous, dense canopy. Perennial leaf stalks of moss have a fairly large size. In the lower part of the stem, rhizoids develop (a primitive analogue of the roots).

Next is the main horizontal stem without leaves. Then a secondary erect stalk is formed up to 15 cm in length. Individual specimens can reach 30 cm. The secondary stem thickly covers the likeness of leaves. The internal structure of the cuckoo moss is represented by a primitive vascular system, through which water and nutrients move along the stalk to the leaves. Some stem cells are elongated and connected in pairs, designed exclusively for transporting water. The lower leaves on the stem do not develop, but remain in the form of scales.